Hello Al.

Al variables are local.
I have changed the name of the variables so there is no conflict possible.
Even more weird, I tried the following code:

		campos1=''
		set textmerge to  MEMVAR campos1
		set textmerge on noshow
		FOR i=1 TO lnCampos
			IF ASCAN(TblFields, UPPER(This.iadata[i,1]) )>0
				\\<<ALLTRIM(UPPER(This.iadata[i,1]))>> ,
			ENDIF
		endfor
		set textmerge off
		set textmerge to

and this does not work either, when the string reaches the dreaded limit . For a strange thing, if I replace the old code:

			FOR k=1 TO lnCampos
				IF ASCAN(TblFields, UPPER(this.iaCampos[k]))>0
					zz=this.iaCampos[k]+","
					MESSAGEBOX(zz+" "+STR(len(This.Campos)) +" "+ This.Campos )
						This.Campos=This.Campos+zz
				END

with this

			FOR k=1 TO lnCampos
				IF ASCAN(TblFields, UPPER(this.iaCampos[k]))>0
					zz=this.iaCampos[k]+","
					MESSAGEBOX(zz+" "+STR(len(This.Campos)) +" "+ This.Campos )
						This.Campos=This.Campos+"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" + zz
				END

the variable reaches 900 chars before it bombs, instead of 500.